Hamstring injury rates have increased during recent seasons and now constitute 24% of all injuries in men's professional football: the UEFA Elite Club Injury Study from 2001/02 to 2021/22

Abstract

Objectives: To: (1) describe hamstring injury incidence and burden in male professional football players over 21 seasons (2001/02 to 2021/22); (2) analyse the time-trends of hamstring muscle injuries over the most recent eight seasons (2014/15 to 2021/22); and (3) describe hamstring injury location, mechanism and recurrence rate.

Methods: 3909 players from 54 teams (in 20 European countries) from 2001/02 to 2021/22 (21 consecutive seasons) were included. Team medical staff recorded individual player exposure and time-loss injuries. Time-trend analyses were performed with Poisson regression using generalised linear models.

Results: 2636 hamstring injuries represented 19% of all reported injuries, with the proportion of all injuries increasing from 12% during the first season to 24% in the most recent season. During that same period, the percentage of all injury absence days caused by hamstring injuries increased from 10% to 20%. Between 2014/15 and 2021/22, training hamstring injury incidence increased (6.7% annually, 95% CI 1.7% to 12.5%) as did burden (9.0% annually, 95% CI 1.2% to 18.3%). During those years, the match hamstring injury incidence also increased (3.9% annually, 95% CI 0.1% to 7.9%) and with the same trend (not statistically significant) for match hamstring injury burden (6.2% annually, 95% CI -0.5% to 15.0%).

Conclusions: Hamstring injury proportions-in number of injuries and total absence days-doubled during the 21-year period of study. During the last eight seasons, hamstring injury rates have increased both in training and match play.

Keywords: Athletic Performance; Epidemiology; Hamstring Muscles; Injuries; Soccer.

Figure 1

Development of hamstring injury incidence and injury burden over the study period. Injury incidence is defined as the number of injuries per 1000 hours of exposure, presented with 95% CI. Injury burden is defined as the number of absence days caused per 1000 hours of exposure and is presented as the mean of participating teams with SD. The shaded area represents the most recent eight-season period which has not been previously published.

Figure 2

Development of the proportion of all reported injuries that were diagnosed as hamstring injuries and the proportion of all injury absence days caused by hamstring injuries over the study period. The shaded area represents the most recent eight-season period which has not been previously published.

Figure 3

Distribution of different hamstring injury types and locations in different periods of matches. Asterisks indicate significantly different proportions of biceps femoris to semimembranosus/semitendinosus or functional to structural injuries.